React Performance Optimization

Performance is crucial for user experience. Let's explore techniques to make your React apps blazing fast.

Understanding Re-renders

React re-renders a component when its state or props change. Unnecessary re-renders are the most common performance issue.

Memoization

React.memo

Wrap components that receive the same props frequently:

const ExpensiveComponent = React.memo(({ data }) => {
  return <div>{/* expensive rendering */}</div>
})

useMemo and useCallback

const expensiveValue = useMemo(() => computeExpensiveValue(data), [data])
const handleClick = useCallback(() => doSomething(id), [id])

Code Splitting

Split your bundle to load only what's needed:

const HeavyComponent = lazy(() => import('./HeavyComponent'))

function App() {
  return (
    <Suspense fallback={<Spinner />}>
      <HeavyComponent />
    </Suspense>
  )
}

Virtual Lists

For long lists, use virtualization:

npm install @tanstack/react-virtual

Profiling Your App

Use React DevTools Profiler to identify bottlenecks.

Conclusion

Performance optimization is an ongoing process. Measure first, then optimize based on real data.